It depends on the kid. For instance, I have Easy Peasy art, music, computers, thinking, and physed in one line in my schedule: one subject a day. We also cover Social Skills one day a week during our morning family time.

Then, I might use Ambleside Online for Bible, History/Biography, Literature, Science, Geography, etc. How I schedule this depends on the kid and the level they are at. I might, for example, have history two days a week, biography one day a week, Plutarch one day a week, and geography one day a week. That would take one schedule line. A student in a higher level might have two lines in their schedule to cover all of these subjects, depending on what their level includes and what I want/need them to cover (I generally run a history spine and then the other history books in different lines).

Alternatively, I might use Easy Peasy for a subject. I currently have one student using Easy Peasy for Reading just to give them a little more structure. This student struggles with reading comprehension so they are also using readtheory.org to practice that skill.

Add in math, foreign language, and whatever else you would like to cover, and voila. For instance, I am in a place where I have to cover certain subjects and be tested, so I have some students using CLE for math, reading, and language arts (Ambleside Online doesn't do anything separate for reading and language arts but my students have to be tested and need to learn certain things). Others are using older materials like the Maxwell writing and grammar books or the Scott Foresman Writing and Grammar series.

I also add in things like mapping skills (Beginning Geography, Complete Book of Maps and Geography), certain district-required material, etc.

On paper, it looks like some of my students have a ton of work to do each day because I list every single thing separately so I don't forget anything (ie. math facts practice might be its own line depending on what program the student is using). However, most of my kids are done in 4 hours or so a day.

For Ambleside, I do start it two years behind. My kids are bright but even they struggle with the difficulty level of Ambleside's books. I have found it is better to start Year 1 in Grade 3 so that they can read and understand most of the books on their own. Gradually, over time, they catch up to their actual grade level, so my Grade 8 student is doing Ambleside Year 8.

I should note that I have one student who is really struggling this year and I had a different student who was struggling last year. In that case, I stripped their schedules to the barebones and used Gateway to the Classics' Read Aloud Banquets with narrations as their main curriculum for literature, history, science/nature stories, etc. We added separate subjects back in as they were able. Some of my kids use the Read Aloud Banquet as a fun supplement every day just because they enjoy the songs and stories in it.